Psion Siena General Maintenance

The Siena with its detachable top casing removed, showing the two AAA cells and the backup cell. There is no external power socket, so those cells are the machine's only supply.

Preventive maintenance for the Psion Siena (1996).

The Siena runs the same SIBO architecture as the Series 3a, but it is a different, smaller machine in a different case — so the Series 3 hinge, button bar and battery-lead procedures do not apply. What it has instead is a set of concerns of its own, and most of them come back to power.

⚠️ Safety

No mains voltages, and — unusually — no mains socket at all. The Siena has no external power input. Everything is CMOS; use an anti-static strap when the machine is open.

Batteries — the Siena's central maintenance issue

Power

Item	Specification
Main	2 × AAA cells
Backup	CR1620 lithium coin cell
External	None. There is no socket.

Three things follow from that, and together they make battery discipline more important on a Siena than on any other SIBO machine:

• You cannot run it from the mains while you work on it. On a Series 3 you can pull the AA cells and keep the machine alive on an adapter. On a Siena you cannot — the backup cell is the only thing holding your data during a change.
• AAA cells hold roughly a third of the energy of AAs, so the Siena is emptying its cells faster than a Series 3 does for the same use.
• The backup cell therefore matters more here than anywhere else in the range. Replace the CR1620 on a schedule, not on failure.

The cells and the backup cell sit in a compartment below a detachable casing in the top of the device. Check the casing clips and the contacts whenever it is off.

Remove the AAA cells for storage and back up first. A leaked AAA in a machine this small has very little distance to travel before it reaches something important.

The serial port carries everything

With no internal SSD bays, the serial port is the machine's only route in and out — PC connectivity, the external SSD or PC-Card drive, and the Travel Modem all go through it.

• Keep the connector clean and its cover closed. A dirty or damaged serial port effectively bricks the machine's ability to exchange data.
• The connector matches the 3c, not the Series 3 or 3a.
• Keep the accessories with the machine. Without the cable and the external drive there is no way to get data off a Siena.
• Keep the infrared window clean, next to the serial port — it is the only wireless route.

Case, keyboard and screen

• The Siena is a smaller, lighter clamshell at 150 × 73 × 19 mm and 183 g. It has none of the Series 3's four-hinge button-bar arrangement, so the Series 3 hinge repair does not apply — but the lid still deserves the same discipline: open it squarely, to a comfortable angle, and stop.
• The keyboard is 48 keys plus 8 application buttons and a separate numeric keypad beside the screen. Clean the membrane and pads as on any Psion — warm water and washing-up liquid for the membrane, isopropyl alcohol on a lint-free swab for the pads, no abrasives.
• The screen is 240 × 160 with no backlight. A Siena that seems dim in poor light is behaving normally.

Capacitors

Not a recap candidate. The Siena is a low-voltage SIBO machine of the same generation and construction as the Series 3 family, with no bulk electrolytic smoothing stage and no community history of recapping. See the reasoning in Psion Series 3a General Maintenance.

Preventive maintenance checklist

1. Back up through the serial port before doing anything else — you have no other route.
2. Remove the AAA cells for storage; inspect the compartment and contacts for corrosion.
3. Replace the CR1620 if you do not know its age.
4. Check the detachable top casing clips and seats properly.
5. Clean the serial connector and the infrared window.
6. Confirm the external drive is recognised, if you have one.
7. Clean the keyboard membrane and pads if any key needs a hard press.

Recommended tools

• Jeweller's screwdrivers, plastic spudgers, anti-static strap.
• Isopropyl alcohol, lint-free and foam swabs.
• Fresh AAA cells and a CR1620.
• The Siena serial cable — the 3c/Siena type, not the 3/3a one.

See Recommended Tools for the general workshop kit.

Related pages

• Psion Siena · Psion Siena Troubleshooting Guide
• Psion Series 3a General Maintenance — the shared SIBO material
• Battery Explosion, Capacitor or Corrosion Damage · Recommended Tools